Fuel Consumption and Cars
Jack Keef General Motors, an automobile dealer in Lincoln, Nebraska, advertised a $9.99 40-point safety checkup for any car and claimed that the service department would finish the job in less than 30 minutes. A local newspaper reporter selected a random sample of 58 customers who took advantage of the dealer's offer and found the sample mean time to complete the safety checkup was x‾ = 32.2 minutes. Assume σ = 5.7 and use a = 0.01.
a. Is there any evidence to suggest that the true mean time to complete the safety checkup is greater than 30 minutes?
b. Find the p value for the hypothesis test in part (a).